Stereoselective Nucleophilic Addition Reactions of Reactive Pseudopeptides

Bis (μ-tetrazolato-NN′) bridged dinuclear nickel(II) Schiff base complexes: Tandem synthesis, structure and self assembly

Abstract Two new bis(μ-tetrazolato-NN′) bridged dinuclear nickel(II) Schiff base complexes [Ni2L12(PTZ)2]·2(CH3)2SO·2.69H2O (1) and 2[Ni2L22(PTZ)2]·3H2O (2) (HL1 and HL2 are Schiff bases, HL1 = 2-((2-(dimethylamino)ethylimino)methyl)phenol, HL2 = 2-((2-(methylamino)ethylimino)methyl)-6-methoxyphenol and HPTZ is 5-pyrazinyltetrazole) have been synthesized via [3+2] cyclo-addition of 2-cyanopyrazine and sodium azide in presence of nickel(II) acetate tetrahydrate and the respective Schiff bases. The structures of the complexes are confirmed by single crystal X-ray diffraction analysis. Both complexes show fluorescence. The change in the denticity of the Schiff base blocking ligand is shown to …

Heterotope Wirtmoleküle zur Einlagerung von zwei verschiedenen Gästen

Organotin(IV) complexes with tetraethyl ethylene- and propylene-diphosphonates

The series of organotin halide complexes with tetraethyl ethylene- and propylene-diphosphonates R n SnX 4-n .L [n=0, X=Cl; n=1, R=Me, X=Cl, Br; n=1, R=Ph, X=Cl; n=2 R=Me, Et, Bu, X=Cl, Br; n=2, R=Ph, X=Cl; L=(EtO) 2 P(O)CH 2 CHR'P(O)(OEt) 2 , R'=H, Me] were synthesized and characterized by means of NMR and Mossbauer spectroscopy. The crystal structure of the complex of diphenyltin dichloride with propylenediphosphonate was determined. The complex consists of polymer chains with bridging bidentate ligands and an octahedral tin environment containing two types of phosphoryl fragments. All of the R 2 SnX 2 adducts have trans-R 2 SnX 4 geometries of tin coordination octahedra according to the q…

Phosphoraneiminato complexes of manganese and cobalt with heterocubane structure

The phosphoraneiminato complexes [MnBr(NPEt3)]4 (1) and [M4Br5{NP(NMe2)3}3] with M = Mn (2) and M = Co (3) are prepared by melting reactions from the anhydrous metal dibromides with the silylated phosphaneimines Me3SiNPR3 (R = Et, NMe2) in the presence of potassium fluoride. All complexes are characterized by crystal structure analyses. 1 forms an only slightly distorted Mn4N4 heterocubane skeleton with an approximate Td symmetry and short Mn…Mn distances of average 295.7 pm. In the structures of 2 and 3 one μ3-NPEt3 ligand of 1 is replaced by one bromine atom with μ3-function. This leads to the novel heterocubane type M4N3Br with approximate C3 symmetry. The deformation of the cubic skelet…

ChemInform Abstract: Stereoselective Nucleophilic Addition Reactions of Reactive Pseudopeptides.

Kronenether mit einem Lewis-sauren Zentrum, eine neue Klasse heterotoper Wirtmoleküle

A ferromagnetic tetranuclear nickel(II) Schiff-base complex with an asymmetric Ni4O4 cubane core

Abstract The ferromagnetic tetranuclear nickel(II) complex [Ni4(L)4(CH3OH)2]·2MeOH·8H2O (1) has been synthesized by reacting nickel nitrate hexahydrate with the Schiff base ligand H2L (H2L = N-(2-hydroxyphenyl)-3-methoxy-salicylideneamine). Complex 1 was characterized by analytical, thermogravimetric, optical and magnetic techniques. The solid state structure of 1 was established by single crystal X-ray diffraction analysis. Crystal structure determination shows the formation of a distorted Ni4O4 cubane moiety encapsulated by four Schiff base ligands. Compound 1 crystallizes in the triclinic space group P 1 ¯ with a = 12.7624(9) A, b = 15.0477(9) A, c = 16.8589(10) A, α = 94.732(2)°, β = 94…

Co-crystallization of Keggin type polyoxometalates [HL]3[PW12O40] and [Ln(DMF)8][PW12O40] (Ln=La, Dy, Yb) (L=N-(2-hydroxyphenyl)-3-methoxy-salicylideneamine): Syntheses, structures and magnetic properties

Abstract Four new Keggin type polyoxometalate clusters [HL]3[PW12O40]·5MeOH (1) and [Ln(DMF)8][PW12O40] {Ln = La (2), Dy (3), Yb (4)} (L = N-(2-hydroxyphenyl)-3-methoxy-salicylideneamine) have been synthesized. Co-crystallization of complex 1 with each of the three complexes 2–4 takes place when the Schiff base ligand is treated with hydrated phosphotungstic acid, H3[PW12O40]·xH2O, hydrated lanthanide nitrate, Ln(NO3)3·6H2O in the presence of Ni(NO3)2·6H2O. The Schiff base ligand is protonated in complex 1 and thus it is neutralizing the charge of the polyoxotungstate anion, [PW12O40]3−. A dimethylformamide (DMF) coordinated trivalent lanthanide ion balances the negative charge of the polyo…

CCDC 968535: Experimental Crystal Structure Determination

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CCDC 1021604: Experimental Crystal Structure Determination

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CCDC 1419401: Experimental Crystal Structure Determination

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CCDC 1021611: Experimental Crystal Structure Determination

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CCDC 1419400: Experimental Crystal Structure Determination

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CCDC 1419402: Experimental Crystal Structure Determination

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CCDC 1419403: Experimental Crystal Structure Determination

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